#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
1->1
2->2 4 8 6
3->3 9 7 1
4->4 6
5->5
6->6
7->7 9 3 1
8->8 4 2 6
9->9 1
0->0
*/
int ultima_cifra(int x)
{
    switch(x%10)
    {
        case 1: return 1;
        case 2:
            switch(x%4)
            {
                    case 0: return 6;
                    case 2: return 4;
            }
        case 3:
            switch(x%4)
            {
                    case 1: return 3;
                    case 3: return 7;
            }
        case 4: return 6;
        case 5: return 5;
        case 6: return 6;
        case 7:
            switch(x%4)
            {
                    case 1: return 7;
                    case 3: return 3;
            }
        case 8:
            switch(x%4)
            {
                    case 0: return 6;
                    case 2: return 4;
            }
        case 9: return 9;
        case 0: return 0;

    }
}
int main(void)
{
    int nr_valori,i,j;
    int suma;
    char x[200];

    FILE* f=fopen("cifra.in","rt");
    FILE* g=fopen("cifra.out","wt");

    fgets(x,1000,f);

    nr_valori=atoi(x);

    for(i=0;i<nr_valori-1;i++)
    {
        suma=0;

        fgets(x,1000,f);

        if((x[strlen(x)-3]-48)<=0)
            for(j=1;j<=(x[strlen(x)-2]-48);j++)
        {
            suma+=ultima_cifra(j);
            suma=suma%10;
        }
        else
        for(j=1;j<=(x[strlen(x)-2]-48)+(x[strlen(x)-3]-48)*10;j++)
        {
            suma+=ultima_cifra(j);
            suma=suma%10;
        }

        fprintf(g,"%d\n",suma);
    }

        suma=0;

        fgets(x,1000,f);

        if((x[strlen(x)-2]-48)>0)
        for(j=1;j<=(x[strlen(x)-1]-48)+(x[strlen(x)-2]-48)*10;j++)
        {
            suma+=ultima_cifra(j);
            suma%=10;
        }
        else
            for(j=1;j<=(x[strlen(x)-1]-48);j++)
        {
            suma+=ultima_cifra(j);
            suma%=10;
        }
        fprintf(g,"%d\n",suma);


    return 0;

}